Verify what a FastAPI deploy actually shipped via /openapi.json

A deploy script that checks "commit X is on main" and then builds HEAD of main can ship teammates' commits too, and a teammate may have deployed their own branch in between, so the live image is not the commit you think. Before trusting that a feature is live, diff the running API's schema: curl /openapi.json and check components.schemas.<Model>.properties for the new fields. ECS DescribeServices gives the image tag; if that tag is not on any remote ref (deleted PR branch), the schema probe is the only cheap proof. Also check prerequisites of other merged PRs (new secrets in the task definition, Lambda env) before redeploying main, since a gated route with an unset token takes the website down.